Lipids: Triglycerides, Phospholipids, and Sterols Flashcards
Lipid family includes…
Triglycerides, Phospholipids, and Sterols
Lipids composed of three fatty acids attached to glycerol
Triglyceride
Explain the structure of a Fatty acid
A chain of carbon and hydrogen atoms with an acid group and a methyl group on each end
acid group in fatty acids
COOH
how many carbons are in the chains of the most occurring fatty acids
even number of carbons of up to 24 carbons in length
simplest 18-carbon fatty acid
Stearic acid
- long chain fatty acids
- medium chain fatty acids
- short-chain fatty acids
- 12 to 24 carbons
- 6 to 10 carbons
- less than 6 carbons
fatty acids that has all its hydrogen atoms and only has single bonds
saturated fatty acids
a double bond in a chain of carbon in fatty acids
point of unsaturation
fatty acids that are missing hydrogen and has double bonds
unsaturated fatty acids
example of a monounsaturated fatty acid and where to find it
Oleic acid
- olive oil and canola oil
two examples of poly unsaturated and where to find them
linoleic acid
- sunflower, safflower, corn, and soybean oils, walnut oil
linolenic acid
- soy bean and canola oils, flax seeds, and walnuts, fish oil
what creates triglycerides
condensation reaction
takes a hydrogen from the glycerol and an OH from the acid end of the fatty acid creating H2O
what affects the firmness of fats
- degree of unsaturation: unsaturated fats are liquid at room temperature. The more saturated or the less double bonds - the more solid.
- the length of carbon chain: the shorter the length of the carbon chain, the softer at room temperature
what, when exposed to, causes fatty acids to rot?
oxygen
what is the most susceptible type of fatty acid to oxygenation? what is the least?
- polyunsaturated is the most susceptible
- saturated is the least
where can you find saturated fats?
- coconut oil
- butter
- palm oil
- pork fat
- chicken fat
where can you find monounsaturated fats?
- olive oil
- peanut oil
- canola oil
where can you find Omega 6 (Linoleic acid)?
- safflower
- sunflower
- cornoil
- soybean oil
- walnut oil
- cotton seed oil
where can you find omega 3 (Linolenic acid)?
- Flaxseed oil
- fish oil
- canola oil
`How can manufacturers protect fat from oxygenation?
- sealing in airtight, non-metallic container
- add antioxidants to compete for oxygen
- Hydrogenation: saturating points of unsaturation
- What is it called when the hydrogen beside a double bound is on the same side?
- what is it called when the hydrogen atoms beside the double bond are on opposite sides?
- Cis-
- Trans-
Trans fatty acids
- behave more like saturated fats
- increases blood cholesterol and risk of heart disease
what makes up only 5%of lipids in the diet?
Phospholipids and Sterols
- what is the best known phospholipid?
- describe its structure
- Lecithin
- structure includes glycerol, two fatty acid chains, and choline on the third site
what is the commercial use for phospholipids?
-emulsifier: due to the hydrophobic fatty acid and the hydrophilic phosphate group
Where can phospholipids be found? where can lecithin?
- phospholipids are used in mayonnaise, salad dressings, and candybars
- lecithing are found in foods like eggs, liver, soybean, wheatgerm, and peanuts.
- what are sterols?
- what is the most well known
- compounds with a multiple ring structure
- cholesterol
- Where can you find cholesterol?
- what sterol do you find in plants?
- what do plant sterols do?
- food derived from animals: meats, eggs, seafood, poultry, and dairy products.
- sterols other than cholesterol
- plant sterol inhibit the absorption of cholesterol which lower blood cholesterol.
What is the role of cholesterol?
cholesterol serve as the starting materials to synthesize:
- bile acids
- sex hormones( testosterone, androgen, estrogen)
- adrenal hormones(cortisol, cortisone, aldosterone)
- Vitamin D
- cell membranes
Cholesterol harmful effects in the body occur when?
-they build up in arteries that cause plaque which lead to Artherosclerosis (a disease that causes heart attack and stroke)
goal of lipid digestion
breakdown and dismantle triglycerides into small molecules
lipid digestion in the mouth
- hard fats begin to melt once it reaches body temperature
- (in infants) the tongue releases lingual lipase that digests fatty acid chains in milk
lipid digestion in stomach
- little digestion occurs
- churning grinds and mixes the chyme into smaller, finer particles. this exposes the fat for attack for gastric lipase enzyme
lipid digestion in smaller intestine
- releases cholecystokinin
- bile is released from gallbladder
- bile acts as en emulsifier drawing fats to water fluids
- fats are fully digested by lipase enzyme from pancrease and small intestine
- where major hydrolysis of triglycerides occur
where does bile go after emulsifying fat?
- recycled and reused
- excreted reducing blood cholesterol
How are lipids absorbed?
- Small(less than 6 carbon)
- medium(6 to 10 carbon)
- Large(12-24 carbon)
- Small, medium lipids, and glycerol diffuse easily into intestinal cells then absorbed directly into the blood stream
- large molecules like long fatty acid chains are emulsified forming micells then diffuse into intestinal cell where triglycerides resemble.
how are lipids transported.
a group of vehicles known as lipoproteins
four types of lipoproteins
- chylomicrons
- Very low density lipoproteins (VLDL)
- Low Density lipoproteins(LDL)
- High density Lipoproteins(HDL)
Chylomicrons
what does it transport
- Largest and least dense
- mostly triglycerides via lymph system from the small intestine
What is the most active site for lipid synthesis?
Liver
What do VLDL carry?
Lipids made from the liver and collected from remnants of chylomicrons
What happens to VLDL as it travels around the body?
VLDL becomes smaller as it cells continue to remove triglycerides becoming LDL
Where is HDL made and what for?
HDL is made in the liver to remove cholesterol from cells and bring it back to the liver for disposal or recycling
Associated with risk for heart disease
High LDL and low HDL
what are some roles of triglycerides in the body?
- energy
- insulation
- shock absorption
- maintaining cell membrane
where are lipids stored?
virtually unlimited storage capacity in adipose tissue
if fat is stored anywhere else that is nonadipose cell?
it is toxic and unhealthy
protein that help regulate energy balance and influence several body functions
adipokines: released by adipose tissue
obesity increases and decreases the release of what?
- increases resistin: promotes inflammation and insulin resistance
- decreases adiposetin: protects against inflammation, diabetes, and heart disease
essential fatty acids ( must be supplied by diet)
Omega 3- linolenic acid
Omega 6- Linoleic acid
Roles of Omega 3
- critical role in optimal function of cells
- normal growth
- visual acuity
- cognitive development
- found abundantly in eyes and brain
- eicosanoids from omega 3
- eicosanoids form omega 6
- help lower BP, prevent blood clot, protect against irregular heart beat, and reduces inflammation
- promote blood clot, inflammation, and blood vessel constriction.
omega 6 to omega 3 ration
4:1 to 10:1
fatty acid deficiency can cause?
- growth retardation
- reproductive failure
- skin lesions
- kidney and liver disorder
- neurological and visual problems
hydrolizes triglycerieds from circulating lipoproteins
lipoprotein lipase
what can you use to predict if a person is at risk of heart attack?
LDL cholesterol
what do saturated fats do?
raise cholesterol and promote blood clotting
how can you reduce saturated fat intake?
- select lean cuts of meat
- skinless poultry
- fat free milk products
what do trans fats do?
raise LDL and lower HDL
too much omega 3 can cause?
- increase bleeding time
- interfere with wound healing
- raise LDL cholesterol
- suppress immune function
Very lean option
-Chicken no sking
-COD
-flounder, trout, tuna
legumes
lean option
beaf or pork chicken no skin herring salmon tuna
medium fat option
ground beef, eggs, tofu
high fat option
bacon hot dogs, sausages, peanut butter, nuts
Monounsaturated fat sources
- Avocado
- nuts
- canola, olive, peanut, sesame oils
- olives
- peanut butter
- sesame seeds
Omega 6 sources
margarin
- mayonnaise
- pine nuts, walnuts
- cotton seed oil, corn oil, safflower oil, soy bean oil
- salad dressing
- sunflower seeds
omega 3 sources
- fatty fish
- flax seeds, chia seeds
- marine algae
- walnuts
- canola and flax seed oil
- yeast
